The present invention relates to a steering system for a train of vehicles or cars which do not move on rails.
It is known to provide a conveying system, particularly for mining applications, wherein a series of conveyors are mounted on wheels so as to make the system transportable. Because of the manner in which mines are developed and extended, it may be necessary for the rather long conveyor system to be moved along a substantially curved or zig zag course. This has made it difficult in the past and time consuming to move the conveyor system when this is required. It will be appreciated that movement of the conveyor system is required fairly frequently as the mining machine advances in the mine.
Attempts have been made in connection with a movable conveyor system to have each vehicle track in a true manner behind the vehicle in front of it. One such system is disclosed in U.S. Pat. No. 4,382,607 issued May 10, 1983 to Edward T. Voight. This known system uses an elongated steering bar pivotably connected to each of adjacent vehicles at end portions of the bar permitting angular orientation of each vehicle in respect to the steering bar and other vehicles. Each end of the steering bar is linked to the near pair of vehicle wheels through wheel yoke pivot arms about king pin type pivots. Movement of the steering bar about its pivotal connection is said to provide proportional turning of the wheels to affect steering and tracking of one vehicle following another in either direction.
U.S. Pat. No. 3,788,444 issued Jan. 29, 1974 to Joseph McWilliams also describes a steering control for a power driven mobile conveyor. The conveyor frame is provided with a pair of wheels at each end with one wheel being power driven and the other wheel being of the idler caster type. The driven wheel is selectively power steerable about a vertical axis through a range of 180 degrees or more. The steerable wheels may be positioned transversely, longitudinally or diagonally of the conveyor frame.
It is an object of the present invention to provide an improved system for steering a plurality of vehicles in a train, which train may comprise a mobile conveyance system.
It is a further object of the invention to provide a steering system for a plurality of vehicles with a number of pairs of steerable propelling devices or wheels, said system including a control mechanism for controlling power means for steering each pair of propelling devices behind the first pair.
The steering system disclosed herein operates by determining the current steering angle of the pairs of steerable propelling devices or wheels in the system and by determining the amount of time the propelling devices in the train have been travelling in order to calculate the location of each pair of steerable propelling devices in the train, except for the first pair of steerable propelling devices on the loading or rear end vehicle. This computer operated system is able to set the steering angle of each of the trailing pairs of steerable wheels so that they will have the same steering angle as the first pair of wheels had when they were at the same location. In this way, each car in the train will accurately track the path of movement of the end vehicle, which in the case of a conveyor system is the rear end vehicle.